Download Module 5 review 1) What is the name of the following picture? Based

Module 5 review
1) What is the name of the following picture? Based on this picture do they have any
genetic abnormalities? Based on this picture is the person male or female?
2) What is the difference genetically in somatic cells and gametes? Where are
somatic cells in the human body and where do you find gametes?
3)Define autosomal chromosomes vs Sex chromosomes. How many pairs of
autosomal chromosomes does a human have and how many pairs of sex
chromosomes?
4) Review the cell cycle:
-Does cytokinesis occur before or after Mitosis? Why?
REMEMBER THAT IF YOU SPEED UP THE CELL CYCLE TOO MUCH YOU
DEVELOP CANCER
5) Review mitosis
6) Review Meiosis
Meiosis Part 1
Meiosis Part 2
7) Compare and contrast Mitosis and Meiosis
8) What is oogenesis? And spermatogenesis? Do these processes involve mitosis or
meiosis?
9) Explain the following chart by matching the phases (G1,G2,S, Mitosis to the
correct steps on the graph)
10) Define the following terms:
a. chromatids b. chromosomes c. chromatin d. homologous chromosomes
-make sure in your definition you explain hw each term is different.
11) REMEMBER THE FUNCTION OF MITOSIS IS TO MAKE DAUGHTER CELLS/
NEW CELLS –this is usually done to replace dead or injured tissues and occurs in
all cells to a varying degree (i.e. skin cells get replaced every 24 hrs where as for
nervous tissue this occurs more slowly if at all)
THE FUNCTION OF MEIOSIS IS TO MAKE SEX CELLS THAT HAVE ½ THE
GENETIC CONTENT OF THE ORIGINAL CELL-this only occurs in specialized
tissue in the ovary and in the seminiferous tubules of the testis.
12) If there were 23 homologous pairs of chromosomes in the body cells of an organism,
how many chromosomes will be in the final haploid number of cells by meiosis?
13) If there were 82 chromosomes in the body cells of an organism, how many
chromosomes will be in the final haploid number of cells by meiosis?
14) If there were 82 chromosomes in the body cells of an organism, how many
chromosomes will be in the cells created my mitosis?
Review Nondisjunction:
15) What was Mendel’s principle of segregation?
16) Define
a) homozygous
b) heterozygous
c) homozygous dominant
d) homozygous recessive
e) Genotype
f) phenotype
g) Alleles
h) gene locus
i) P1 generation
j) F1 generation, F2 generation
17) Review the: Test Cross - A test cross is used to determine the genotype of a
dominant phenotype. i.e. If a plant is tall with round seeds, all you know about the
genotype is that the plant must carry the dominant allele for round and tall. – you don’t
know if it is heterozygous or homozygous dominant. By crossing the unknown plant
with a homozygous recessive plant, you can determine its genotype
18 Review Punnett Squares for monohybrid and dyhibrid crosses:
Punnett Squares
- an easy way to follow the inheritance of single traits (the result of monohybrid
crosses) or two traits (dihybrid crosses)
monohybrid cross:
Mom’s gametes
from her genotype – BB
B
Dad’s gametes
from his genotype ->
bb
B
b Bb
Bb
b Bb
Bb
Mom’s gametes
Offspring genotype
ex. A plant grown from heterozygous smooth seeds is crossed with a plant
grown from wrinkled seeds. Determine the phenotype and genotype of the
offspring.
S
s
s Ss
ss
s Ss
ss
Summary:
50% Ss (heterozygous): phenotype smooth
50% ss (homozygous recessive ): phenotype
wrinkled
Multiple Alleles:
Incomplete dominance
The lack of a dominant gene, where the offspring show a blending of the two
traits (red & white flowers produce pink flowers) – interact to produce a new
phenotype (also known as intermediate dominance)
Codominance, another type of incomplete dominance, involves the expression of
both alleles at the same time – ex. hair on shorthorn cattle – red (Hr) is
codominant to white (Hw). When mixed, a roan calf – with both white and red
hair, genotype HrHw is produced.
ABO & Rh blood grouping
- mixture of codominance and dominance. In humans, there are three alleles
in basic blood grouping – A, B, O, and two alleles for the rhesus factor (Rh +
or -)
- A and B are both dominant to O
- A and B are codominant
- the Rh + is dominant to the Rh – gene
Phenotype
A
B
AB
O
Genotype(s)
IAIA, IAIO
IBIB, IBIO
IA IB
IOIO
Mapping Genes
Gene Linkage & Crossing Over
When crosses involving two or more traits don’t yield the expected phenotypic
results – due to the linkage effect of genes on the same chromosome
ex: wing shape and body colour don’t seem to sort independently in fruit
flies. When curved wings/black body colour flies are crossed with straight
wings/normal body colour, instead of 9:3:3:1 phenotypic ratio, there is the
3:1 ratio found when only a monohybrid cross is done
** genes on the same chromosome tend to segregate together – Linked genes
BUT! Crossing-over will sometimes cause linked genes to be split up
- The closer two genes are on the same chromosome, the more likely that
they will stick together
- The farther apart two genes are on the same chromosome, the more likely
they will segregate separately due to crossing over.
The position of the genes on the chromosome can be mapped using the
crossover %
- the higher the % of crossing over, the farther apart the genes are on the
chromosome
- 1% in crossover = 1 map unit away from each other
- using many crossover frequencies, genes can be mapped on each of the
chromosomes – all map distances are additive, so many genes can be
mapped
- ex: if crossover between A & C is 3%, A and B is 8% and B and C is 5%,
locate the genes along the chromosome
A
3
C
5
8
B